Method and apparatus for sealing cartons by suction



May 1947- R. M. DUNNING 2,419,991

METHOD AND APPARATUS FOR SEALING CARTONS BY SUCTION Filed Jan. 4, 1945 2 Sheets-Sheet l May 6,1947

R. M. DUNNING 2,419,991 METHOD AND APPARATUS FOR SEALING CARTONS BY SUCTION Filed Jan. 4, 1945 1 l i I as iq a7 2.9 A/ v I as '44 a5 I 2 Sheets-Sheet 2 Q Patented May 6, 1947 METHOD AND APPARATUS FOR SEALING CARTONS BY SUCTION Robert M. Dunning, St. Paul, Minn., assignor to Waldorf Paper Products Company, St. Paul, Minn, a corporation of Minnesota Application January 4, 1945, Serial No. 571,334

14 Claims.

My invention relates to an improvement in method and apparatus for sealing cartons by suction and deals more particularly in a method and apparatus which holds the flaps of a glued end carton in contact during the setting of the adhesive.

In a co-pending application I have described the method whereby the cartons after the gluing operation may pass beneath a suction head to pull the innermost flaps of a series of superimposed flaps into contact with the outermost flaps of the carton. While the present construction is somewhat similar to that described in my co-pending application, the present invention embodies the use of suction cups or the like which extend through apertures in one or more of the superimposed closure flaps into engagement with the innermost flaps of the carton.

A feature of the present invention resides in the fact that actual contact exists between the inner flaps of the carton and the suction applying means used in conjunction therewith. As a result there is little or no likelihood that the flaps will not be engaged by the suction cups and there is little or no tendency to partially evacuate the air from the interior of the carton.

Where the suction is exerted to the entire top of the sealed carton and where the inner flaps are not properly constructed, there is a possibility that the inner flaps will catch against the side walls of the carton and be frictionally held from raising into engagement with the overlying flaps for at least a short period of time. In this event the air is partially evacuated from the i terior of the carton and the pressure on both sides of the lowermost sealin flaps is equalized, thus preventing proper operation of the sealing apparatus.

In the present construction suction cups actually contact the innermost flaps of the carton and pull these flaps into sealin relation. The suction cups may be mounted for vertical movement or may be held in place suspended above the lowermost sealed flaps, extending through suitable apertures in at least one of the overlying laminations of the top closure.

A feature of the present invention resides in the fact that the apertures through which the suction cups extend may be in both of the overlying closure flaps and may be in registry so that the suction cups may extend through both of the upper laminations of the closure. Alternately, however, these suction cups may extend merely through apertures in the lamination next adjacent the lowermost closure flaps and may be covered by an additional outer flap which acts to seal the openings.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

Figure 1 is a perspective View of a carton upon which my method and apparatus may operate.

Figure 2 illustrates the carton of Figure l in sealed condition.

Figure 3 shows a partially closed carton of a somewhat different type from that illustrated in Figures 1 and 2.

Figure 4 is a view of the carton shown in Figure 3 after an additional closing operation has been performed.

Figure 5 is a diagrammatic elevational view of an apparatus for filling, closing and sealing the cartons.

Figure 6 is an elevational sectional view of a portion of the apparatus shown in Figure 5.

The cartons A illustrated in Figures 1 and 2 of the drawings include a tubular body H) which preferably comprises four rectangularly arranged side walls and a bottom closure wall which is preferably sealed over a mandrel. In the completed cartons the uppermost end or the end of the carton last sealed may actually comprise the bottom of the carton insofar as the printing and design is concerned. As the bottom closure ll may be of any suitable type it is not described herein in detail.

A pair of closing flaps l2 and 13 issue from opposed side walls of the carton and opposed flaps l4 and 55 are hingedly secured to the remaining side walls of the carton. When the carton is sealed, the flaps i2 and I3 are first folded into the position shown in Figure 1 of the drawings and later the flap id is folded to overlie the flaps l2 and i3. The flap i5 is then folded upon the flap I l. Adhesive is preferably applied to the exposed surfaces of the top when the carton is in the position shown in Figure 1, thus providing a layer of adhesive between the flaps I2 and I3 and also between the flaps l 4 and I5.

Apertures it are formed in the flap M and expose a portion of each of the flaps l2 and I3 spaced from any edge thereof. The flap I5 is likewise provided with apertures I! therethrough which are in registry with the apertures l6 when the flaps are folded as illustrated in Figure 2. Thus a portion of the central part of each of the flaps l2 and i3 is exposed when the carton is sealed.

In Figures 3 and 4 of the drawings, I disclose a carton B which is similar in many respects to the carton A and is provided with a similar bottom closure, not illustrated. A pair of exposed closing flaps l9 and 20 are hingedly connected to two opposed side walls of the carton and flaps 2| and 22 are hingedly secured to the remaining exposed side walls. The flaps l9 and 29 are designed to first fold into opposed relation as illustrated in Figure 3 of the drawings. Adhesive is then ap-. plied to the upper exposed surfaces of the flaps, the flap 2| is folded to overlie the flaps I9 and 29, and finally the flap 22 is folded to overlie the flap 2|.

The flap 2| is provided with spaced apertures 23 therethrough which expose a central portion of each of the flaps I9 and 29 spaced from the edges thereof. The flap 22 is imperforate and acts to cover the apertures 23 when the carton is completely sealed.

In Figure of the drawings I diagrammatically illustrate a structure for sealing the various cartons A or B. A conveyor belt 24 operating in the direction of the arrow 25 is supported by pulleys 26 and 21 at opposite ends thereof. The cartons A are fed onto the conveyor belt 24 and are maintained in place by side guides 21. Supporting rollers or a supporting plate 29 underlie the upper exposed surface of the conveyor 24 so a to properly support the conveyed cartons.

The cartons are placed on the conveyor with the various flaps of the cartons in vertical position. The cartons successively pass beneath the filling head 39 where each carton is individually filled. The cartons then are engaged by a folding bar 3| on each side of the carton,'which folds the opposed flaps I4 and I5 of the cartons A outwardly into horizontal position. While in this position the flaps rest upon supporting rails such as 32 which'later close the flaps as will be pointed out. A hook shaped arm 33 engages the rearmost flap such as l3 to fold the same into horizontal position and the remaining opposed flap I2 is pressed into place by means of a presser foot 34. This action folds the various flaps into the position shown in Figure 1 of the drawings. The carton then passes beneath a glue wheel 35 which applies glue to the necessary surfaces. One rail 32 then continues to provide a folding arm 36 which acts to fold the first folded flap M in position to overlie the flaps l2 and I3. The remaining rail 32 is provided with a folding arm 31 which acts to fold the remaining. flap l5 to overlie the flaps M. The carton is then sealed and completely closed.

A second conveyor 39 is supported by end pulley 40 and 4| to overlie the tops of the cartons to hold the flaps in sealing relation. The conveyor 39 is preferably provided with registering means 42 which engage a wall of the carton to hold the carton in proper registry with the belt 39. Suction cups 43 are also provided in the conveyor belt 39. These suction cups are designed to pass through the apertures Hi and H into engagement with the upper surface of the flaps I2 and I3 to hold these flaps elevated during the setting of the adhesive.

The suction cups 43 are provided with the usual tapered edge 44 which comes to a feather edge at its point of contact with the flaps l2 and I3. A hollow shank 45 on each suction cup communicates with the interior of the cup and permits the air within the suction cup to be partially evacuated. The shanks 45 extendthrough the conveyor belt 39 so that suction on one side or the 4 belt may be transmitted through the belt and into the suction cups.

A suction conduit 46 is mounted over a lowermost portion of the conveyor belt 39 in opposed relation to the tops of the cartons A. This suction conduit 46 holds the belt 39 against the edges thereof, thus sealing the belt to the suction conduit. As best illustrated in Figure 6 of the drawings, however, a carton A having flaps I2 and I3 which are bent downwardly into the interior of the carton, as illustrated at the left hand side of Figure 6 of the drawings, may have these flaps pulled into sealing relation by the suction cups 43 as illustrated at the right in Figure 6 of the drawings.

In place of the cartons A the cartons B may be employed. In this event the rail 32 associated with the flap 22 must be of sulficient length to extend past the conveyor 39 before the folding arm end 31 thereof folds the flap 22 into carton sealing position. As the exposure to air of the surface of the flap 22 to which adhesive has been applied for an extended period of time may dry the adhesive, it is preferable to employ an additional glue seal which contacts the flap 22 before the sealing thereof. This structure is, however, alternative, and need not be employed if found unessential. As the manner in which the glue seal and folding arm may operate to later fold the flap 22 is believed obvious, this structure has not been specifically shown in the drawings.

My structure has been found extremely practical for the sealing of glued end cartons and for holding the innermost flaps up against the remaining flaps during the setting of the adhesive. The opposed flaps have a tendency to curl into the carton after glue has been applied thereto, both due to the tendency of moisture to curl the flaps and also due to the downward pressure exerted against the top closure. With my construction, however, a tight seal may be effected and a, carton may be produced which will not sift or leak at the corners.

In accordance with the patent statutes, I have described the principles of construction and operation of my method and apparatus for sealing cartons by suction, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A method of sealing cartons having a closure including laminations in which at least the lamination outwardly of the innermost lamination has apertures therethrough, the method including the steps of applying suction means directly to the surface of the innermost lamination, and pulli g these laminations up into contact with the apertured lamination,

2,. The method of sealing a carton having a series'of laminations, at least the lamination directly outwardly of the innermost lamination having apertures therethrough, the method including the steps of inserting suction applying means through the laminations, and pulling the innermost laminations up into contact with the outer lamination.

3. The method of sealing a carton having a series of laminations forming the closure, at least the lamination next adjacent the innermost lamination having apertures therethrough, the method consisting of applying adhesive between the innermost lamination and the next adjacent lamination, inserting the suction applying means through the apertures into engagement with the innermost lamination, and drawing the innermost lamination into contact with the apertured lamination.

4. A carton sealing means for use in combination with cartons having a series of flaps forming the closure, at least the fiap next adjacent the innermost flap having apertures therethrough, the apparatus comprising suction cup means, and means supporting said suction cup means to extend through the laminations into contact with the innermost flap of the closure, said suction cups holding said innermost flap in engagement with the next adjacent flap.

5. A carton sealing means for use in combination with cartons having a closure comprising a series of flaps in surface contact, at least the flap next adjacent the innermost flap having apertures therethrough, the apparatus comprising means for conveying cartons, suction cup means supported adjacent said conveyor means, said suction cup means supported to extend through said apertures to hold the innermost flap against the next adjacent flap.

6. A carton sealing means for use in' combination with cartons having a closure comprising a series of flaps adapted to lie in surface contact, at least the flap next adjacent the innermost flap having apertures therethrough, the apparatus comprising carton closing means, suction cup means, means supporting said suction cup means over said cartons to extend through said apertures into engagement with the innermost flap to hold the same against the next adjacent flap.

7. A carton sealing means for use in combination with cartons having a series of flaps in surface contact, at least the flap next adjacent the innermost flap having apertures therethrough, the apparatus comprising a conveyor, suction cup means, means supporting said suction cup means to move with said conveyor, said suction cup means extending through said apertures to engage and support the innermost flap of said series of flaps.

8. A carton sealing means for use in combination with cartons having a series of flaps in surface contact, at least the flap next adjacent the innermost flap having apertures therethrough, the apparatus comprising a conveyor, a second conveyor movable above said first conveyor, suction cups carried by one of said conveyors, said suction cups engageable with the .nnermost flap through said apertures to support ;he innermost flap as the cartons move along iaid conveyors.

9. A carton sealing apparatus for use in com- )ination with cartons having an end closure in- :luding a series of laminations, at least the lamition cups supported by said second conveyor and extendable through said apertures into engagement with the innermost lamination of said carton.

10. A carton sealing apparatus for use in combination with cartons having an end closure including a series of laminations, at least the lamination next adjacent the innermost lamination having apertures therethrough, the apparatus comprising a conveyor, a second conveyor movable with said first conveyor, a series of suction cups supported by said second conveyor and extendable through said apertures into engagement with the innermost lamination of said carton, and means for applying suction to said suction cups.

11. The method of sealing cartons having a closure including laminations in which at least one lamination outwardly of a second lamination has an aperture therethrough, the method including the steps of applying suction means directly to the surface of the second lamination, and. pulling the second lamination up into contact with the apertured lamination.

12. The method of sealing a carton having a series of laminations forming the closure, at least one of the laminations overlying a second lamination having an aperture therethrough, the method consisting of applying adhesive between the second lamination and the apertured lamination, inserting the suction applying means through the aperture into engagement with the second lamination, and drawing this second lamination into contact with the apertured lamination.

13. A carton sealing means for use in combination With cartons having a series of flaps forming the closure, at least one flap outwardly of a second flap having an aperture therethrough, the apparatus comprising suction cup means, means supporting said suction cup means to extend through the aperture into contact with the second flap, said suction cups holding said second flap in engagement with the apertured flap,

14. A carton sealing means for use in combination With cartons having a series of flaps in surface contact, at least one flap outwardly of a second flap having an aperture therethrough, the apparatus comprising a conveyor, suction cup means, means supporting said suction cup means to move with said conveyor, said suction cup means extending through said aperture to engage and support said second flap against said apertured flap.

ROBERT M. DUNNING. 

